Reciprocal recurrent selection effects on the genetic structure of tropical maize populations assessed at microsatellite loci

Maize (Zea mays L.) is one of the crops in which the genetic variability has been extensively studied at isoenzymatic loci. The genetic variability of the maize populations BR-105 and BR-106, and the synthetics IG-3 and IG-4, obtained after one cycle of a high-intensity reciprocal recurrent selection (RRS), was investigated at seven isoenzymatic loci. A total of twenty alleles were identified, and most of the private alleles were found in the BR-106 population. One cycle of reciprocal recurrent selection (RRS) caused reductions of 12% in the number of alleles in both populations. Changes in allele frequencies were also observed between populations and synthetics, mainly for the Est 2 locus. Populations presented similar values for the number of alleles per locus, percentage of polymorphic loci, and observed and expected heterozygosities. A decrease of the genetic variation values was observed for the synthetics as a consequence of genetic drift effects and reduction of the effective population sizes. The distribution of the genetic diversity within and between populations revealed that most of the diversity was maintained within them, i.e. BR-105 x BR-106 (G ST = 3.5%) and IG-3 x IG-4 (G ST = 4.0%). The genetic distances between populations and synthetics increased approximately 21%. An increase in the genetic divergence between the populations occurred without limiting new selection procedures.

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Genetic-diversity assessed by microsatellites in tropical maize populations submitted to a high-intensity reciprocal recurrent selection

Euphytica ◽

10.1023/b:euph.0000004946.15260.4a ◽

2003 ◽

Vol 134 (3) ◽

pp. 277-286 ◽

Cited By ~ 23

Author(s):

Luciana Rossini Pinto ◽

Maria Lucia Carneiro Vieira ◽

Cláudio Lopes de Souza Jr ◽

Anete Pereira de Souza

Keyword(s):

Genetic Diversity ◽

High Intensity ◽

Recurrent Selection ◽

Reciprocal Recurrent Selection ◽

Tropical Maize ◽

Maize Populations

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Combining Ability and Heterosis of Algerian Saharan Maize Populations (Zea mays L.) for Tolerance to No-Nitrogen Fertilization and Drought

Agronomy ◽

10.3390/agronomy11030492 ◽

2021 ◽

Vol 11 (3) ◽

pp. 492

Author(s):

Meriem Riache ◽

Pedro Revilla ◽

Oula Maafi ◽

Rosa Ana Malvar ◽

Abderahmane Djemel

Keyword(s):

Zea Mays ◽

Stress Tolerance ◽

Nitrogen Fertilization ◽

Recurrent Selection ◽

Zea Mays L ◽

Base Material ◽

N Fertilization ◽

Nitrogen Stress ◽

Reciprocal Recurrent Selection ◽

Maize Populations

Drought and low nitrogen are major stresses for maize (Zea mays L.), and maize populations from the Sahara Desert are potential sources of stress tolerance. The objectives were to assess the tolerance and varietal and heterosis effects of Algerian populations under no-nitrogen fertilization and water stress. A diallel among six Algerian maize population was evaluated under drought (300 mm irrigation) vs. control (600 mm) and no-nitrogen fertilization vs. 120 kh ha−1 N fertilization. Genotypes showed significant differences and genetic effects for water- and nitrogen-stress tolerance. We propose a reciprocal recurrent selection to take advantage of additive and non-additive effects, using AOR and IGS, since they showed good performance in optimum and stress conditions, for improving yield heterosis for AOR × IGS. Negative effects are not expected on plant height, anthesis–silking interval or early vigor. These populations and BAH could be sources of inbred lines tolerant to drought and no-nitrogen fertilization. There was no relationship between origin and genetic group and stress tolerance per se or as parents of tolerant crosses. These populations and crosses could be used as base material among Algerian populations, for breeding programs focusing on tolerance to water or nitrogen stress.

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